1. Field of the Invention
This invention relates to an image forming apparatus in which a light beam is adopted as an exposure source.
2. The Prior Art
The market for desktop type printers has developed remarkably in recent years. In particular, use of electrophotographic-type laser-beam printers has rapidly become widespread owing to the image quality and high speed of these printers. Technological progress has been accompanied by a reduction in the size and price of these printers, and large numbers of printers for personal use have appeared on the market. In order to satisfy the need for more natural representation of character fonts and multi-tone representation of graphic images, printers are required to have a higher resolution and an improved multi-tone capability.
However, in a case where a digital image is expressed with the conventional products, the pixel array is a lattice-like matrix array, and therefore the occurrence of a so-called "jagged" image cannot be avoided when reproducing slanting or oblique lines. Even if a somewhat higher resolution is provided, the oblique-line portions of character fonts and the representation of graphic images still develop pronounced jaggedness and the apparent quality of image data representation declines.